Document FR 2 958 980 describes an example of a known straightener device, comprising an annular body, vanes attached to the annular body and a platform positioned between each pair of adjoining vanes. Such a straightener device is generally heavy, which is harmful to the performance of the turbomachine. Moreover, the manufacture of the platform, as well as the mounting of the platform between each pair of adjoining vanes, are long and complex operations.
There exists, therefore, a need for a straightener device for a turbomachine which is lighter and whose manufacture and assembly are facilitated.